Method for determining prostate carcinoma

Abstract

The present invention relates to a method for determining prostate carcinoma, including obtaining a ratio 1 between an amount of a free prostate specific antigen and an amount of a free PSA having an α(2,3) glycan, the free PSA having an α(2,3) glycan being a free prostate specific antigen having a glycan in which a terminal sialic acid residue of the glycan is α(2,3)-linked to a second galactose residue from a terminal of the glycan, in a sample derived from a subject; obtaining a ratio 2 between the ratio 1 and a volume of the prostate of the subject; and determining prostate carcinoma based on the obtained ratio 2.

1 . A method for determining prostate carcinoma, comprising:
 obtaining a ratio 1 between an amount of a free prostate specific antigen and an amount of a free PSA having an α(2,3) glycan, the free PSA having an α(2,3) glycan being a free prostate specific antigen having a glycan in which a terminal sialic acid residue of the glycan is α(2,3)-linked to a second galactose residue from a terminal of the glycan, in a sample derived from a subject;   obtaining a ratio 2 between the ratio 1 and a volume of the prostate of the subject; and   determining prostate carcinoma based on the obtained ratio 2.   
     
     
         2 . The method for determining prostate carcinoma according to  claim 1 , wherein a method for measuring the amount of the free PSA having an α(2,3) glycan is a method including:
 reacting the free PSA having an α(2,3) glycan with an affinity substance having an affinity for an α(2,3) glycan, the affinity substance being a substance having an affinity for a glycan in which a terminal sialic acid residue of the glycan is α(2,3)-linked to a second galactose residue from the terminal of the glycan, to form a complex of the free PSA having an α(2,3) glycan and the affinity substance having an affinity for an α(2,3) glycan; 
 measuring an amount of the complex; and 
 obtaining an amount of the free PSA having an α(2,3) glycan based on obtained measurement results. 
 
     
     
         3 . The method for determining prostate carcinoma according to  claim 2 , wherein the affinity substance having an affinity for an α(2,3) glycan is a lectin. 
     
     
         4 . The method for determining prostate carcinoma according to  claim 3 , wherein the lectin is a  Maackia amurensis  lectin. 
     
     
         5 . A method for obtaining data for carrying out a prostate carcinoma determination, comprising:
 obtaining a ratio 1 between an amount of a free prostate specific antigen and an amount of a free PSA having an α(2,3) glycan in a sample derived from a subject; and   obtaining a ratio 2 between the ratio 1 and a volume of the prostate of the subject.   
     
     
         6 . A kit for determining prostate carcinoma, comprising:
 (1) an affinity substance having an affinity for an α(2,3) glycan; and   (2) an instruction manual that describes a determination procedure including obtaining a ratio 1 between an amount of a free prostate specific antigen and an amount of a free PSA having an α(2,3) glycan in a sample derived from a subject; obtaining a ratio 2 between the ratio 1 and a volume of the prostate of the subject; and determining prostate carcinoma based on the obtained ratio 2.